The complicated novel Possession  by A. S. Byatt is a double-tiered romance and a literary brainteaser. Like John Fowles's The French Lieutenant's Woman or Tom Stoppard's play Arcadia, the two works it most resembles, the novel seesaws across two centuries. Roland Michell and Maud Bailey are late 20th-century British literary scholars. Following clues that have eluded generations of biographers and critics, they discover a romantic link between the subject of his research, Randolph Ash, and the subject of hers, Christabel LaMotte, a pair of mid-19th-century poets. As Roland and Maud immerse themselves in this discovery, they too begin to fall in love. It's an in­genious story, although a reader can get bogged down in Byatt's too-clever literary parodies. Those who prefer their 19th-century novels to be written by Austen or Eliot may feel the urge to skim the lengthy correspondence between the poets; those who feel that, as a literary gamesman, Byatt falls short of, say, Nabokov may grow restive during the long pages devoted to Ash's and LaMotte's poetry.

The movie Possession pares down Byatt's 550-plus pages down to a neat hour and three-quarters by eliminating all the literary self-consciousness. Otherwise, it makes only minor alterations, such as changing Roland from a Brit to an American so that filmmaker Neil LaBute could cast his favorite actor, Aaron Eckhart, as Roland. Eckhart starred in LaBute's first two pictures, In the Company of Men and Your Friends and Neighbors, though most viewers will recognize him as Julia Roberts's long-suffering biker beau in Erin Brockovich. Eckhart works hard to repay LaBute's confidence, but you can feel the strain in his performance: he simply isn't convincing as a young man for whom scholarship has a sensual appeal.

The real case of miscasting here, though, is LaBute himself. If you've seen his other films, such as Nurse Betty, you're justified in fearing the worst--LaBute movies made before Possession lack the smallest impulse of generosity toward the characters. It's a huge relief to find that he hasn't projected his trademark smugness and mean-spiritedness onto Byatt's novel, but a lack of nastiness is a negative virtue, and that and his technical proficiency are the only positives in Possession.